I’m Kayla, and I’ve handled a lot of cash. Farmer’s markets. Garage sales. Coffee stands. You name it. I’ve had real money, and yes, I’ve had fakes slip in. It stings. But you learn fast.
Here’s what I do now, and the tools that helped me. Real stories included. No fluff.
The day a $20 taught me a hard lesson
I got a $20 at my yard sale. Seemed fine. Crisp, kinda stiff. I bought groceries with it later, and the cashier looked at me with that look. She held it to the light. No thread. No watermark. My stomach sank. The store kept it. I walked out minus the milk and the cash.
It wasn’t fun, but it changed how I check money.
Feel comes first
Real bills feel different. They’re cotton and linen, not just paper.
- Rub your thumb on the shoulders of the portrait. It should feel a little rough.
- Bend the bill. It shouldn’t crack or flake ink.
- Old bills feel soft but still strong. Fakes feel waxy or too smooth.
When I trained my hands at the coffee shop, I’d line up a real $20 and a “maybe” $20. Close my eyes. Touch both. The fake felt… flat.
Tilt and look—fast checks that save you
- On $10, $20, $50, and $100 bills, the number in the lower right changes color when you tilt it. My $20s shift from copper to green. If it stays dull, I pause.
- On the new $100, there’s a blue ribbon. When you tilt it, the little bells move. They should really move. Printed fakes don’t.
One time, a guy handed me a $100 at a craft fair. The blue ribbon looked drawn on. I tilted it. Nothing moved. I smiled, handed it back, and asked for a card payment. He left fast.
Hold it to the light—watermark and thread
This is the one I teach my friends, because it’s simple and strong.
- Watermark: Hold the bill up to a light. You should see a faint face that matches the portrait. On a $20, you should see Jackson. If the face doesn’t match, or you see nothing, big red flag.
- Security thread: Also hold to light. You’ll see a thin strip with tiny words. Its spot and glow color change by bill:
- $5: Thread is left of Lincoln. It glows blue under UV.
- $10: Right of Hamilton. It glows orange.
- $20: Left of Jackson. It glows green.
- $50: Right of Grant. It glows yellow.
- $100: Left of Franklin. It glows pink.
At a food truck gig, my UV light showed a $20 thread that glowed blue. That was wrong. A $20 should glow green. We caught it on the spot.
Tiny words, big truth: microprinting
Real bills have tiny words that are hard to fake.
- On $20s, check “USA TWENTY” near the portrait.
- On $100s, look near Franklin’s collar and around the gold “100.”
- If the tiny text looks like mush or dots, I call it.
I keep a small loupe in my apron. Sounds extra, but it saves time.
For a compact, university-backed cheat sheet on what to look for, I keep the Detect Counterfeit U.S. Currency guide from Cornell on my phone.
If you want to browse side-by-side photos of genuine versus forged bills, I keep an updated gallery on PrettyFakes that you can check anytime. I also maintain a continuously updated, in-depth breakdown of every counterfeit-detection gadget I personally trust, and you can find that full gear list right here.
Serial numbers should match
There are two serial numbers on the front. They should match each other and fit the bill’s look and series year. I once saw a $50 with two different numbers. That’s a no.
Three real moments that taught me a lot
- The yard sale $20: No watermark, no thread. I missed both. That mistake cost me twenty bucks. It also made me start checking every bill while I’m still face to face.
- The vending machine trick: I fed a $10 into a soda machine. It kept spitting it out. I checked. The paper felt off, and the color-shift “10” didn’t shift. Machines can be fussy, sure, but they’re not dumb.
- The holiday market $100: It had a real watermark but no pink glow on the thread under my UV light. It glowed white. The buyer shrugged and swapped it for smaller bills. Those passed every test.
If your cash dealings ever spill over into face-to-face meet-ups arranged through South Florida classified ads, take a minute to scan the local listings on OneNightAffair’s Backpage Lauderhill board—the daily-updated feed highlights who’s advertising, their preferred payment methods, and practical safety pointers so you can prep your counterfeit checks before you even leave the house.
Incidentally, the same inspection habits saved me when I dipped my toes into bullion—fake gold coins are a real thing. The whole unboxing (and the painful lessons) are in this field report I wrote about the experience of buying bogus coins: I bought counterfeit gold coins—here’s how that went.
The tools I actually use (and what I think)
I’ve tried a few things. Some are great. Some are “meh.” Here’s how they did for me.
Dri Mark counterfeit pen
- What it does: Marks the bill. Real bills stay pale. Many fakes turn dark.
- What I like: Fast. Cheap. Fits in a pocket.
- Where it failed me: A bleached fake $100 passed the pen test. Later, a banker showed me the missing thread and the bad ribbon. So the pen is a quick screen, not proof.
- My take: I still use it for speed, then I do a light check.
Vont UV flashlight (small blacklight)
- What it does: Shows the security thread glow color and some UV marks.
- What I like: Bright for the size. Works in a tent or dim booth. Fast.
- Watch-outs: UV needs lower light. Midday sun can wash it out.
- My take: For me, this is the best low-cost tool. It saved me from that blue-glow “$20.”
AccuBANKER D450 detector
- What it does: Checks multiple things—UV, magnetic ink, infrared patterns. Gives a pass/fail beep.
- What I like: Reliable on $20s and $100s. Staff can use it with almost no training.
- Downsides: Bulky for a small pop-up. Needs a plug. Not cheap.
- My take: I keep it at my coffee stand, not in my tote. It’s my “final say” on big bills.
The U.S. Currency Education Program even publishes a free, picture-heavy Teller Toolkit that mirrors the same steps I use—feel, tilt, and light—so new staff can learn fast.
Community wisdom matters too. I spend part of my Sunday mornings swapping stories with other booth owners in an uncensored forum over at JustBang where the candid threads dish out field-tested tricks for everything from deterring quick-change scams to picking the best portable cash boxes.
Handling physical cash often means checking IDs too—especially if you sell age-restricted items. I ran a gauntlet of dedicated ID scanners and wrote up what actually worked (and what didn’t). You can read that comparison here: I tried counterfeit ID detectors—here’s what actually worked for me.
My quick check flow (takes under 10 seconds)
- Feel the bill. Rough ink? Not too slick?
- Tilt and see if the number shifts color.
- Hold to light. Find the watermark and the thread.
- If it’s a big bill or I feel weird about it, zap it with the UV.
- Still unsure? Compare to a bill you know is real.
If it fails two checks, I don’t take it. I stay calm and ask for a card or smaller bills. No drama.
A few small notes that help a lot
- Compare with a known real bill of the same kind. Side by side tells the truth fast.
- Look at the portrait’s eyes and lines. Real prints have crisp detail. Fakes blur.
- Watch for “too perfect.” Fresh fakes can look oddly shiny or flat.
- Trust your gut, then confirm with light. Feel weird? Check twice.
Final word from a cash person
I wish I never got that fake $20. But it made me better. Now I use my hands, my eyes, and a tiny UV light. I don’t rush. I don’t make it awkward, either. A smile and a quick check go a long way.
And you know what? Cash can be simple again. Touch. Tilt. Light. That rhythm sticks.